scholarly journals The Emerging Role of Amino Acid PET in Neuro-Oncology

2018 ◽  
Vol 5 (4) ◽  
pp. 104 ◽  
Author(s):  
Amer Najjar ◽  
Jason Johnson ◽  
Dawid Schellingerhout
Keyword(s):  
Amino Acid ◽  
Treatment Planning ◽  
Radiation Treatment ◽  
Critical Role ◽  
Therapy Response ◽  
Response Assessment ◽  
Early Therapy ◽  
Contrast Enhanced ◽  
Amino Acid Pet ◽  
Cns Malignancies

Imaging plays a critical role in the management of the highly complex and widely diverse central nervous system (CNS) malignancies in providing an accurate diagnosis, treatment planning, response assessment, prognosis, and surveillance. Contrast-enhanced magnetic resonance imaging (MRI) is the primary modality for CNS disease management due to its high contrast resolution, reasonable spatial resolution, and relatively low cost and risk. However, defining tumor response to radiation treatment and chemotherapy by contrast-enhanced MRI is often difficult due to various factors that can influence contrast agent distribution and perfusion, such as edema, necrosis, vascular alterations, and inflammation, leading to pseudoprogression and pseudoresponse assessments. Amino acid positron emission tomography (PET) is emerging as the method of resolving such equivocal lesion interpretations. Amino acid radiotracers can more specifically differentiate true tumor boundaries from equivocal lesions based on their specific and active uptake by the highly metabolic cellular component of CNS tumors. These therapy-induced metabolic changes detected by amino acid PET facilitate early treatment response assessments. Integrating amino acid PET in the management of CNS malignancies to complement MRI will significantly improve early therapy response assessment, treatment planning, and clinical trial design.

Radiation treatment planning in brain tumours

2008 ◽  
Vol 47 (05) ◽  
pp. 200-204 ◽  
Author(s):  
H. Alheit ◽  
L. Oehme ◽  
C. Winkler ◽  
F. Füchtner ◽  
A. Hoepping ◽  
...  
Keyword(s):  
Amino Acid ◽  
Treatment Planning ◽  
Radiation Treatment ◽  
Tumour Volume ◽  
Tracer Uptake ◽  
Tumour Tissue ◽  
Subtotal Resection ◽  
High Dose ◽  
Radiation Treatment Planning ◽  
Amino Acid Pet

Summary Aim: Amino acid PET has become an important diagnostic tool for brain tumour imaging. In this data analysis, the potential impact of amino acid PET with 3-O-methyl- 6-[18F]fluoro-L-DOPA ([18F]OMFD) on radiation treatment planning is addressed by the following questions: 1. Was tumour tissue identified with OMFD-PET which was not covered by the conventionally derived planning target volume (PTV)? 2. Would the PTV have been changed incorporating OMFD-PET? Patients, methods: OMFD-PET of 25 patients after subtotal resection of malignant glioma was evaluated. The region of elevated tracer uptake of PET and of contrast enhancing masses on MRI were outlined as separate gross tumour volumes (GTVMRI and GTVOMFD) and reconstructed in the planning CT for comparison with the conventionally drawn GTVconv. A PTVnew based on GTVconv+MRI was calculated. Pairwise differential volumes were calculated to estimate overlap and differential volumes delineation by each image modality and the PTVconv and PTVnew respectively. Results: Differential volume analysis showed > 10 cm3 of GTVOMFD outside GTVconv and GTVMRI in 5/25 patients respectively. From GTVMRI >10 cm3 were found outside GTVOMFD in 8/25 patients. Although all tumour areas indicated by [18F]OMFD were covered by the conventionally derived PTV, based on a GTVOMFD+MRI, the PTVnew would have been enlarged >20% in seven patients. In seven patients the PTVnew would have been reduced. Conclusion: OMFD-PET indicated tumour tissue outside the tumour region identified with MRI, adding valuable information for the delineation of the GTV in radiation treatment planning. OMFD-PET contains the potential to tailor the high dose radiation to the appropriate tumour volume, especially if dose escalation is desired.

scholarly journals 32. TREATMENT MONITORING OF IMMUNOTHERAPY AND TARGETED THERAPY USING AMINO ACID PET IN PATIENTS WITH BRAIN METASTASES

2020 ◽  
Vol 2 (Supplement_2) ◽  
pp. ii5-ii6
Author(s):  
Norbert Galldiks ◽  
Diana Abdulla ◽  
Matthias Scheffler ◽  
Fabian Wolpert ◽  
Jan-Michael Werner ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Amino Acid ◽  
Brain Metastases ◽  
Response Assessment ◽  
Diagnostic Value ◽  
Treatment Monitoring ◽  
Fet Pet ◽  
Time To Peak ◽  
Amino Acid Pet

Abstract PURPOSE Recently, the RANO group has analyzed the additional diagnostic value of amino acid PET in patients with primary and secondary brain tumors and recommended the use of this imaging technique in addition to conventional MRI. Here, we investigated the value of PET using the radiolabled amino acid O-(2-[18F]fluoroethyl)-L-tyrosine (FET) for treatment monitoring of immune checkpoint inhibition (ICI) or targeted therapy (TT) alone or in combination with radiotherapy in patients with brain metastases (BM) since contrast-enhanced MRI often remains inconclusive. METHODS We retrospectively identified 40 patients with 107 BM secondary to melanoma (n=29 with 75 BM) or non-small cell lung cancer (n=11 with 32 BM) treated with ICI or TT who had FET PET (n=60 scans) for treatment monitoring from 2015–2019. The majority of patients (n=37; 92.5%) had radiotherapy during the course of disease. In 27 patients, FET PET was used for the differentiation of treatment-related changes from BM relapse following ICI or TT. In 13 patients, FET PET was performed for response assessment to ICI or TT using baseline and follow-up scans (median time between scans, 4.2 months). In all lesions, static and dynamic FET PET parameters were obtained (i.e., mean tumour-to-brain ratios (TBR), time-to-peak values). Diagnostic accuracies of PET parameters were evaluated by receiver-operating-characteristic analyses using the clinical follow-up or neuropathological findings as reference. RESULTS A TBR threshold of 1.95 differentiated BM relapse from treatment-related changes with an accuracy of 85% (P=0.003). Metabolic Responders to ICI or TT on FET PET had a significantly longer stable follow-up (threshold of TBR reduction relative to baseline, ≥10%; accuracy, 82%; P=0.004). Furthermore, at follow-up, time-to-peak values in metabolic responders increased significantly (P=0.019). CONCLUSIONS FET PET may add valuable information for treatment monitoring in BM patients treated with ICI or TT.

scholarly journals Maximizing the use of batch production of 18F-FDOPA for imaging of brain tumors to increase availability of hybrid PET/MR imaging in clinical setting

2020 ◽  
Author(s):  
M S Aboian ◽  
R Barajas ◽  
J Shatalov ◽  
V Ravanfar ◽  
E Bahroos ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Amino Acid ◽  
Brain Tumors ◽  
Pet Imaging ◽  
Critical Role ◽  
Normal Brain ◽  
Mri Imaging ◽  
Pet Tracer ◽  
Amino Acid Pet ◽  
The Cost

Abstract Background Amino acid PET imaging of brain tumors has been shown to play an important role in predicting tumor grade, delineation of tumor margins, and differentiating tumor recurrence from the background of post-radiation changes, but is not commonly used in clinical practice due to high cost. We propose that PET/MRI imaging of patients grouped to the day of tracer radiosynthesis will significantly decrease the cost of PET imaging, which will improve patient access to PET. Methods Seventeen patients with either primary brain tumors or metastatic brain tumors were recruited for imaging on 3T PET/MRI and were scanned on 4 separate days in groups of 3-5 patients. The first group of consecutively imaged patients contained three patients, followed by two groups of 5 patients, and last group of 4 patients. Results For each of the patients, standard of care gadolinium enhanced MRI and dynamic PET imaging with 18F-FDOPA amino acid tracer was obtained. The total cost savings of scanning 17 patients in batches of 4 as opposed to individual radiosynthesis was 48.5% ($28,321). Semiquantitative analysis of tracer uptake in normal brain were performed with appropriate accumulation and expected subsequent washout. Conclusion Amino acid PET tracers have been shown to play a critical role in characterization of brain tumors but their adaptation to clinical practice has been limited due to high cost of PET. Scheduling patient imaging to maximally utilize the radiosynthesis of imaging tracer significantly reduces the cost of PET and results in increased availability of PET tracer use in neuro-oncology.

scholarly journals Advantages and limitations of amino acid PET for tracking therapy response in glioma patients

2019 ◽  
Vol 20 (2) ◽  
pp. 137-146 ◽  
Author(s):  
Karl-Josef Langen ◽  
Alexander Heinzel ◽  
Philipp Lohmann ◽  
Felix M. Mottaghy ◽  
Norbert Galldiks
Keyword(s):  
Amino Acid ◽  
Therapy Response ◽  
Amino Acid Pet

scholarly journals Radioprotective Agents and Enhancers Factors. Preventive and Therapeutic Strategies for Oxidative Induced Radiotherapy Damages in Hematological Malignancies

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1116
Author(s):  
Andrea Gaetano Allegra ◽  
Federica Mannino ◽  
Vanessa Innao ◽  
Caterina Musolino ◽  
Alessandro Allegra
Keyword(s):  
Radiation Treatment ◽  
Protective Action ◽  
Critical Role ◽  
Therapy Response ◽  
Hematologic Malignancies ◽  
Tumor Control ◽  
Post Irradiation ◽  
Normal Tissues ◽  
Wide Range ◽  
Other Substances

Radiation therapy plays a critical role in the management of a wide range of hematologic malignancies. It is well known that the post-irradiation damages both in the bone marrow and in other organs are the main causes of post-irradiation morbidity and mortality. Tumor control without producing extensive damage to the surrounding normal cells, through the use of radioprotectors, is of special clinical relevance in radiotherapy. An increasing amount of data is helping to clarify the role of oxidative stress in toxicity and therapy response. Radioprotective agents are substances that moderate the oxidative effects of radiation on healthy normal tissues while preserving the sensitivity to radiation damage in tumor cells. As well as the substances capable of carrying out a protective action against the oxidative damage caused by radiotherapy, other substances have been identified as possible enhancers of the radiotherapy and cytotoxic activity via an oxidative effect. The purpose of this review was to examine the data in the literature on the possible use of old and new substances to increase the efficacy of radiation treatment in hematological diseases and to reduce the harmful effects of the treatment.

210 Contrast Enhanced Endoscopic Ultrasound of the Colon Is a Marker of Early Therapy Response Following Anti-TNF-Therapy in Patients With Acute Ulcerative Colitis

2015 ◽  
Vol 81 (5) ◽  
pp. AB124
Author(s):  
Mark Ellrichmann ◽  
Johannes Bethge ◽  
Alexander Arlt ◽  
Sebastian Zeissig ◽  
Berenice Brandt ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Endoscopic Ultrasound ◽  
Therapy Response ◽  
Early Therapy ◽  
Contrast Enhanced

scholarly journals Differential Spatial Distribution of TSPO or Amino Acid PET Signal and MRI Contrast Enhancement in Gliomas

2021 ◽  
Author(s):  
Lena Kaiser ◽  
Adrien Holzgreve ◽  
Stefanie Quach ◽  
Michael Ingrisch ◽  
Marcus Unterrainer ◽  
...  
Keyword(s):  
Amino Acid ◽  
Contrast Enhancement ◽  
Specific Binding ◽  
Differential Information ◽  
Moderate Correlation ◽  
Mri Contrast ◽  
Contrast Enhanced ◽  
Amino Acid Pet ◽  
Small Overlap ◽  
Contrast Enhanced Mri

In this study dual PET and contrast enhanced MRI were combined to investigate their correlation per voxel in patients at initial diagnosis with suspected glioblastoma. Correlation with contrast enhancement (CE) as an indicator of BBB leakage was further used to evaluate whether PET signal is likely caused by BBB disruption alone, or rather attributable to specific binding after BBB passage. PET images with [18F]GE180 and the amino acid [18F]FET were acquired and normalized to healthy background (TBR). Contrast enhanced images were normalized voxel by voxel with the pre-contrast T1-weighted MRI to generate relative CE values (rCE). Voxel-wise analysis revealed a high PET signal even within the sub-volumes without detectable CE. No to moderate correlation of rCE with TBR voxel-values and a small overlap as well as a larger distance of the hotspots delineated in rCE and TBR-PET images were detected. In contrast, voxel-wise correlation between both PET modalities was strong for most patients and hotspots showed a moderate overlap and distance. The high PET signal in tumor sub-volumes without CE observed in voxel-wise analysis as well as the discordant hotspots emphasize the specificity of the PET signals and the relevance of combined differential information from dual PET and MRI images.

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